Making an evidence and gap map (EGM)

What are evidence and gap maps (EGMs)?  

Campbell EGMs are systematic and visual presentation of the availability of rigorous evidence for a particular policy domain. The EGMs consolidates what we know and do not know about ’what works’ by mapping out existing and ongoing systematic reviews and impact evaluations in this field; and by providing a graphical display of areas with strong, weak or non-existent evidence on the effect of interventions or initiatives. You can read more here.

EGMs show what evidence there is and not what evidence says!

The map is presented in two dimensions: the rows list interventions and sub-categories, and the columns lists the outcome domains. Each cell shows studies which contain evidence on that combination of intervention and outcome. Included studies are coded for additional characteristics which can be used in filters, such as country, region and population categories.

The evidence is identified by a search following a pre-specified, published search protocol. The map is accompanied by a descriptive report to summarize the evidence for stakeholders such as researchers, research commissioners, policy makers, and practitioners.

EGMs are useful for policymakers and practitioners looking for evidence to inform policies and programs. For donors and researchers, these maps can inform a strategic approach for commissioning and conducting research.

How are Campbell EGMs created?

The essential stage in an EGM is to get the framework right which in turn depends on the scope of the map. Existing typologies of interventions and outcomes are especially useful if they are widely accepted in the relevant community. This involves formation of formal advisory board consisting of experts in the area, policy makers, and international and national research organizations.

The advisory board should be consulted to advice on sources to develop the framework, databases and organizations to include in searches, identification of key stakeholders and review of reports.

EGMs include both completed and on-going systematic reviews and impact evaluations. The online platform is populated with studies identified using a comprehensive and systematic search strategy documented in a pre-specified protocol. It should follow a clear inclusion and exclusion criteria that are systematically applied and all the included and excluded studies are systematically reported.

So you want to make a Campbell evidence and gap map?

We welcome proposals for new EGMs to be registered with the Campbell Collaboration and, subsequently, published in the Campbell Library.

There are three stages in the production of a Campbell EGM: (1) title registration, (2) protocol, and (3) EGM report. You will find a Word template for each of these three stages, with a 'Campbell template instructions' document in our online library.

The editorial process for your review will be managed by one Campbell’s Coordinating Groups.

1. Title registration

The first step is to complete the Title Registration Form (TRF). Please read the document 'Campbell template instructions' before filling in the form. The proposed title for your EGM should clearly state the scope of the EGM. This scope should be determined in consultation with advisory board and key stakeholders including intended end users.

Guidance on formulating the EGM title may be found in the ‘Campbell Collaboration checklist for evidence and gap maps: Conduct standards’.

The completed TRF should be sent directly to the Managing Editor of the Coordinating Group with which the EGM will be registered. You can expect a response regarding your proposed title within 10 working days.

The approved TRF is published in the Campbell Library.

2. Protocol

The next stage is to develop the EGM protocol. In addition to following the template, authors may consult the Protocol guidelines document.

Guidance on formulating the EGM protocols may be found in the ‘Campbell Collaboration checklist for evidence and gap maps: Conduct standards’. It is important that these guidelines are adhered to ensure that your EGM can be published in the Campbell Library. Although the list of requirements may seem quite long, they are the building blocks of a high quality EGM, and most of the items are very straightforward to implement.

The protocol you submit will be reviewed though a process managed by one Coordinating Group’s Editors. It will be sent for external refereeing by both a content expert and a methods specialist. The Editor will provide you with a consolidated set of comments with guidance on required revisions. These comments are often more detailed than those you may be used to from the usual journal refereeing process. There may be more than one round of refereeing.

The approved protocol is published in the Campbell Library.

Once the protocol is approved, the review team is required to sign an agreement with the Coordinating Group which lays out the roles and responsibilities of each.

3. EGM report and online map

After the protocol is accepted, the work of generating the EGM itself begins. All the steps of an EGM from screening to coding should be done using platform EPPI reviewer. After the protocol is registered, the managing editor of your group will provide you and your team with an Eppi-reviewer license. 

The EGM report should be prepared using the review template, available from our online library, along with template instructions. The 'Campbell checklist for evidence and gap maps: Reporting standards' gives more details on how specific parts of the EGM report should be presented.

The EGM report will be sent for external refereeing, usually by the same referees as commented on the protocol. The Editor will provide you with a consolidated set of comments with guidance on required revisions. More than one round of refereeing may be necessary.

The completed review should be submitted with an Agreement that you will update the EGM regularly, subject to availability of resources.

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